SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04308ba3f27531cefd4188b8d7a1fdb2258bade7c78a5a1141af31dbbc62db3d' 
  AND token = 'vD9LUWdZMNwOQfXsDV+qFjWImTu0hIJOEdJyff4DwIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}