perf(api): utilize the message_workflow_run_id_idx while querying messages (#32944)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/tasks/app_generate/workflow_execute_task.py

@@ -321,7 +321,13 @@ def _resume_app_execution(payload: dict[str, Any]) -> None:
                 return
 
             message = session.scalar(
-                select(Message).where(Message.workflow_run_id == workflow_run_id).order_by(Message.created_at.desc())
+                select(Message)
+                .where(
+                    Message.conversation_id == conversation.id,
+                    Message.workflow_run_id == workflow_run_id,
+                )
+                .order_by(Message.created_at.desc())
+                .limit(1)
             )
             if message is None:
                 logger.warning("Message not found for workflow run %s", workflow_run_id)