SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fac84d15d4ebf59a3831cc41ace7ce64516deffe868563cc1539896501a008d' 
  AND token = 'KFqMFoyM8jAy3iGZ9kQQTIKDE1uJbwxkyy96pFGxyh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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