SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ae114cef72123012070b792fa251a790e58155562da08f5e74bde4b2813d954' 
  AND token = 'ZVgbA3rJ5caYuoZVD5lueJnRvMrl1PCNZXnAy6iApok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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