SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccba08ea03de5e34f569e0a6acf01e8f0a84c0667618658ed255349919264c9c' 
  AND token = 'Gg2THXxYRz4PlW2NbrCVPIBldJttdGkgqyHoFgScSL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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