SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df9096e41e6cc2351d003805020d523edd60d2fe957b36ce9362d2ffed8ea899' 
  AND token = 'ZUXgkbSq8il2OgeqMzrZ4dJELw+U+DbtBsbvn3WL4iM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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