SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4f725c401d4de4ba57e1d702b247c7ff5ebd88b811a3427f93c6e552ddefaea' 
  AND token = 'nYTCWo9O562gkBauGBYkZ86P3CgvZDrIQrvIzDrI140=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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