SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbde04e6e77299ab50a28942087f8e577493b41d79fcd8c7e96eb4ab1f85d5f9' 
  AND token = 'QfUF+v6kgA0XPN+OD5+Y9P2OVmcB9pwbHKlXRgut3xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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