SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee60a50c22373ce37039fc7f018926bea5c607b8729b88987fe4c2e8b59d5ec' 
  AND token = 'NnJgNPAQN4mPfe+TVJ5HfEqKGHMexRFAUbNMfADpIhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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