SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a33c2cc25e175256afc317017f00f8c75f99ac8ad2ec81fb80749b279859db84' 
  AND token = 'gkfHMWdS0OC++TcJL7BxnJQyyVK0Xnats/80N0XXF2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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