diff --git a/.server-changes/faster-schedule-validation-lookup.md b/.server-changes/faster-schedule-validation-lookup.md
new file mode 100644
index 00000000000..db83ef6b009
--- /dev/null
+++ b/.server-changes/faster-schedule-validation-lookup.md
@@ -0,0 +1,6 @@
+---
+area: webapp
+type: improvement
+---
+
+Creating or updating a schedule, and deploying a project with declarative schedules, is faster in long-lived projects with many deploys.
diff --git a/apps/webapp/app/v3/services/checkSchedule.server.ts b/apps/webapp/app/v3/services/checkSchedule.server.ts
index beb5de4b596..0115c742069 100644
--- a/apps/webapp/app/v3/services/checkSchedule.server.ts
+++ b/apps/webapp/app/v3/services/checkSchedule.server.ts
@@ -45,6 +45,9 @@ export class CheckScheduleService extends BaseService {
         slug: schedule.taskIdentifier,
         projectId: projectId,
       },
+      select: {
+        triggerSource: true,
+      },
       orderBy: {
         createdAt: "desc",
       },
diff --git a/internal-packages/database/prisma/migrations/20260806100000_add_background_worker_task_project_id_slug_created_at_index/migration.sql b/internal-packages/database/prisma/migrations/20260806100000_add_background_worker_task_project_id_slug_created_at_index/migration.sql
new file mode 100644
index 00000000000..af9400ac60b
--- /dev/null
+++ b/internal-packages/database/prisma/migrations/20260806100000_add_background_worker_task_project_id_slug_created_at_index/migration.sql
@@ -0,0 +1 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS "BackgroundWorkerTask_projectId_slug_createdAt_idx" ON "public"."BackgroundWorkerTask"("projectId", "slug", "createdAt");
diff --git a/internal-packages/database/prisma/schema.prisma b/internal-packages/database/prisma/schema.prisma
index ca1d868ab04..8ea3ea2fc3a 100644
--- a/internal-packages/database/prisma/schema.prisma
+++ b/internal-packages/database/prisma/schema.prisma
@@ -752,6 +752,7 @@ model BackgroundWorkerTask {
   @@unique([workerId, slug])
   // Quick lookup of task identifiers
   @@index([projectId, slug])
+  @@index([projectId, slug, createdAt])
   @@index([runtimeEnvironmentId, projectId])
   @@index([runtimeEnvironmentId, slug, triggerSource])
 }