SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38453c5bfef719f99674997d5cfac9ede9feaa07ecd8372f518d0264109fec64' 
  AND token = 'LTmL1j4wUKcTHuZeiHbXAlQNyQQpYEw7iw/PDOhia6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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