How to check for valid token

How to check for valid token

It is fairly easy to create a new token using the api

  1. https://accounts.zoho.com/apiauthtoken/nb/create?SCOPE=ZohoCRM/crmapi&EMAIL_ID=Zoho CRM Username or Email ID&PASSWORD=Your Zoho CRM Password
But how can I check if I have a token, to see if is valid?

If I call the above code every time I need a token, I just get a new token and before I know it, my list of active tokens is quite long.

Surely not the best approach, so what is the best practice?

Clearly I would like to re-use my token, but if it is no longer valid, I would like to re-issue one, using the code above (1).

I would wish though, that it was posible to add a description to the authentication token created though the api, so it was easier to keep track on what is issued to what.