SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '834617a1ec6cfffe683ea242ba1ad176e883ee0d3677b1df116755285e976b03' 
  AND token = '3V2oi+Cf5gELGdNQEG7bJINacvi1iQIW4Y8KScL+Pho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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