What token do you refer to?
Ie what are you logging in with?
You can create a session while they are unauth:
# Should sessions be established for access to unprotected resources? This
# configuration item is useful when a consistent session identifier is
# required for clients as they transition from unauthenticated to
# authenticated.
create-unauth-sessions = no
But - i'm not sure I understand why you want to keep an old one around.
You could get rid of any 'logged out' cookies:
# Remove the WebSEAL session cookie on logout
logout-remove-cookie = no
But an expired session may still have an old cookie in the browser if they didn't explicitly log out.