SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1079b4df09ee730ba782024f9f79016070060129255645a918c622ac5a4b241e' 
  AND token = 'M4TcjXUOF7fI5Nprli2T7xnfHbRftFggHNWshgxrdi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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