Token expiration in createAccessToken()

Couldn’t find any information regarding the expiration of the token created with createAccessToken(). Was looking into using this as an alternative to the process found in the web services SmartApp authorization.

The issue is, the token provided by createAccessToken() does not have an expiration. The only thing listed in the documentation is that revokeAccessToken() revokes it. I assume that it only able to be used for a limited time as the docs also say that it is only intended to be used for a few minutes during SmartApp setup.

If anyone has attempted this or has any more information regarding this issue, it would be appreciated.