Determine if knack user token has expired

Is there a way to determine if a user token has expired before performing an API call?

Did you find a solution to this issue? Have run into the same thing today with a view based api call that has been working as expected since implemented. Now getting an 403 error (Forbidden), "Invalid token provided. Please reauthenticate." Reauthentication makes no difference.

We're getting invalid tokens for users that have just logged in.  They're occurring randomly.   The error is showing up as a 403 permission denied....  but if you look at the text of the error is says "Invalid Token, please reauthenticate" or something close to that.   

I would also like to know the answer to this question, since I am facing this problem now in my app..