You could conceivably have a login sessions page and access it from a trusted computer to force logout of a session from an untrusted computer.
But it seems the bigger problem with login from a malicious computer is that the computer could do whatever it wants with your session while you're logged in, regardless of how securely you can logout later.
(1) people frequently (and rightly) do that anyway, so we might as well make it less bad.
(2) Building a trustworthy computer is largely about isolating different components in a way that hurts malware more than it does the user-experience. Sticking keys on a USB key is one instance of such isolation.
This would leave a window of x seconds after logging out in which attacks could occur but that could be mitigated by requiring a failed request on logout (perhaps require the usb key to be removed upon logout, send an auth-ping, and only give a successful logout message if the auth-ping fails. (Even without this mitigation I'm not sure what kind of attack would work for the inbetween X seconds, but might as well mitigate it in case someone else could think of something)
Of course there's only so much you can do if your hardware is compromised, you can just try to mitigate the issue as much as possible and hope for the best.
All signed access token, when logged out or revoked, should be marked so on the server side. Of course the untrusted computer should at the very least send the logout request.
Typically, a service should also let you see all your active sessions and let you revoke them.