diff --git a/syncapi/storage/postgres/send_to_device_table.go b/syncapi/storage/postgres/send_to_device_table.go
index fd0c1c56..6ab1f0f4 100644
--- a/syncapi/storage/postgres/send_to_device_table.go
+++ b/syncapi/storage/postgres/send_to_device_table.go
@@ -41,6 +41,8 @@ CREATE TABLE IF NOT EXISTS syncapi_send_to_device (
 	-- The event content JSON.
 	content TEXT NOT NULL
 );
+
+CREATE INDEX IF NOT EXISTS syncapi_send_to_device_user_id_device_id_idx ON syncapi_send_to_device(user_id, device_id);
 `
 
 const insertSendToDeviceMessageSQL = `
diff --git a/syncapi/storage/sqlite3/send_to_device_table.go b/syncapi/storage/sqlite3/send_to_device_table.go
index e3aa1b7a..0da06506 100644
--- a/syncapi/storage/sqlite3/send_to_device_table.go
+++ b/syncapi/storage/sqlite3/send_to_device_table.go
@@ -39,6 +39,8 @@ CREATE TABLE IF NOT EXISTS syncapi_send_to_device (
 	-- The event content JSON.
 	content TEXT NOT NULL
 );
+
+CREATE INDEX IF NOT EXISTS syncapi_send_to_device_user_id_device_id_idx ON syncapi_send_to_device(user_id, device_id);
 `
 
 const insertSendToDeviceMessageSQL = `