It sounds like you don't want to use the token service at all.
The token service is for a very specific use case - if you're just trying to setup authentication to Elasticsearch, then it's not what you need.
You want to start here: https://www.elastic.co/guide/en/x-pack/5.6/how-security-works.html#_user_authentication
If you have a username and password, then you just want to configure your HTTP client to do "Basic authentication". The specifics for that depend entirely on what client you are using to connect to ES.