SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '360b85931b71593c67634fc32688c956c3d547d6f94f218e17b47c6e5ac8f404' 
  AND token = 'bGVYHZY+Yzcx9k0T54sFb6NoloZJZKzJeevwV92ng7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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