diff --git a/apps/api/internal/store/api_key_auth_integration_test.go b/apps/api/internal/store/api_key_auth_integration_test.go
index 8247c5e..f20828f 100644
--- a/apps/api/internal/store/api_key_auth_integration_test.go
+++ b/apps/api/internal/store/api_key_auth_integration_test.go
@@ -65,6 +65,36 @@ func TestVerifyLocalAPIKeyHandlesEightConcurrentRequestsWithFourConnections(t *t
 	}
 }
 
+func TestVerifyLocalAPIKeyCoalescesUsageUpdates(t *testing.T) {
+	db, verificationStore, created, _ := newLocalAPIKeyVerificationFixture(t, 1)
+	ctx := context.Background()
+
+	if _, err := verificationStore.VerifyLocalAPIKey(ctx, created.Secret); err != nil {
+		t.Fatalf("verify local API key first time: %v", err)
+	}
+	var firstLastUsedAt time.Time
+	if err := db.pool.QueryRow(ctx, `
+SELECT last_used_at
+FROM gateway_api_keys
+WHERE id = $1::uuid`, created.APIKey.ID).Scan(&firstLastUsedAt); err != nil {
+		t.Fatalf("read first API key usage timestamp: %v", err)
+	}
+
+	if _, err := verificationStore.VerifyLocalAPIKey(ctx, created.Secret); err != nil {
+		t.Fatalf("verify local API key second time: %v", err)
+	}
+	var secondLastUsedAt time.Time
+	if err := db.pool.QueryRow(ctx, `
+SELECT last_used_at
+FROM gateway_api_keys
+WHERE id = $1::uuid`, created.APIKey.ID).Scan(&secondLastUsedAt); err != nil {
+		t.Fatalf("read second API key usage timestamp: %v", err)
+	}
+	if !secondLastUsedAt.Equal(firstLastUsedAt) {
+		t.Fatalf("usage timestamp changed inside coalescing window: first=%s second=%s", firstLastUsedAt, secondLastUsedAt)
+	}
+}
+
 func newLocalAPIKeyVerificationFixture(t *testing.T, maxConnections int32) (*Store, *Store, CreatedAPIKey, GatewayUser) {
 	t.Helper()
 	db := newIdentityPairingPostgresTestStore(t)
diff --git a/apps/api/internal/store/api_key_auth_test.go b/apps/api/internal/store/api_key_auth_test.go
index 5b8e299..87a4ce4 100644
--- a/apps/api/internal/store/api_key_auth_test.go
+++ b/apps/api/internal/store/api_key_auth_test.go
@@ -3,6 +3,7 @@ package store
 import (
 	"context"
 	"errors"
+	"strings"
 	"testing"
 
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/auth"
@@ -50,6 +51,12 @@ func TestVerifyLocalAPIKeyClosesCandidateRowsBeforeUpdatingUsage(t *testing.T) {
 	if database.updatedAPIKeyID != "matching-key" {
 		t.Fatalf("updated API key = %q, want matching-key", database.updatedAPIKeyID)
 	}
+	if !strings.Contains(database.updateSQL, "set_config('synchronous_commit', 'off', true)") {
+		t.Fatalf("API key usage update did not disable synchronous commit: %s", database.updateSQL)
+	}
+	if !strings.Contains(database.updateSQL, "interval '1 minute'") {
+		t.Fatalf("API key usage update did not coalesce hot-key writes: %s", database.updateSQL)
+	}
 	if user.APIKeyID != "matching-key" || user.GatewayUserID != "user-id" {
 		t.Fatalf("verified user = %+v", user)
 	}
@@ -82,16 +89,18 @@ func TestVerifyLocalAPIKeyReturnsUnauthorizedAfterClosingCandidateRows(t *testin
 type fakeLocalAPIKeyDatabase struct {
 	rows            *fakeLocalAPIKeyRows
 	updatedAPIKeyID string
+	updateSQL       string
 }
 
 func (database *fakeLocalAPIKeyDatabase) Query(context.Context, string, ...any) (pgx.Rows, error) {
 	return database.rows, nil
 }
 
-func (database *fakeLocalAPIKeyDatabase) Exec(_ context.Context, _ string, arguments ...any) (pgconn.CommandTag, error) {
+func (database *fakeLocalAPIKeyDatabase) Exec(_ context.Context, sql string, arguments ...any) (pgconn.CommandTag, error) {
 	if !database.rows.closed {
 		return pgconn.CommandTag{}, errors.New("API key usage update started before candidate rows closed")
 	}
+	database.updateSQL = sql
 	database.updatedAPIKeyID, _ = arguments[0].(string)
 	return pgconn.NewCommandTag("UPDATE 1"), nil
 }
diff --git a/apps/api/internal/store/postgres.go b/apps/api/internal/store/postgres.go
index 9397377..32d36f5 100644
--- a/apps/api/internal/store/postgres.go
+++ b/apps/api/internal/store/postgres.go
@@ -1709,7 +1709,19 @@ WHERE k.key_prefix = $1
 		if bcrypt.CompareHashAndPassword([]byte(candidate.hash), []byte(secret)) != nil {
 			continue
 		}
-		if _, err := database.Exec(ctx, `UPDATE gateway_api_keys SET last_used_at = now(), updated_at = now() WHERE id = $1::uuid`, candidate.apiKeyID); err != nil {
+		// API key usage timestamps are telemetry, not authentication state. Keep
+		// their writes off the synchronous-replication critical path and coalesce
+		// hot-key updates so concurrent requests do not contend on the same row.
+		if _, err := database.Exec(ctx, `
+WITH commit_policy AS (
+  SELECT set_config('synchronous_commit', 'off', true)
+)
+UPDATE gateway_api_keys
+SET last_used_at = now(),
+    updated_at = now()
+FROM commit_policy
+WHERE id = $1::uuid
+  AND (last_used_at IS NULL OR last_used_at < now() - interval '1 minute')`, candidate.apiKeyID); err != nil {
 			return nil, err
 		}
 		return &auth.User{
diff --git a/apps/api/internal/store/worker_registry.go b/apps/api/internal/store/worker_registry.go
index c8dda15..839b621 100644
--- a/apps/api/internal/store/worker_registry.go
+++ b/apps/api/internal/store/worker_registry.go
@@ -46,6 +46,12 @@ func (s *Store) RegisterWorkerInstance(ctx context.Context, input WorkerRegistra
 		return WorkerAllocation{}, err
 	}
 	defer tx.Rollback(ctx)
+	// Worker heartbeats and allocations are ephemeral coordination state that is
+	// refreshed every few seconds. Do not hold the global allocation lock while
+	// waiting for a synchronous replica to acknowledge the commit.
+	if _, err := tx.Exec(ctx, `SELECT set_config('synchronous_commit', 'off', true)`); err != nil {
+		return WorkerAllocation{}, err
+	}
 	if _, err := tx.Exec(ctx, `SELECT pg_advisory_xact_lock(hashtextextended('gateway-worker-capacity', 0))`); err != nil {
 		return WorkerAllocation{}, err
 	}