SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0e9716f44e129caa507113c121c8e0d1b64a21a54bbe1f06e79a796f08593c' 
  AND token = 'xzWMxB+iUlw3VB8Aun/ZG64xqTRmq7s0I+RsVEPLviw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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