SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf007d5e4aa9c780cedee3e80214e664fdb0fc6a520800f715ee866525c1b38' 
  AND token = 'bfjd2OS8QDjzfP0Ed6Ldn+lMFSLBzqhHivqSk29QHng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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