I have been using Yubikeys for years, according to this guide: https://github.com/drduh/yubikey-guide
The nice thing is that using the private key requires physical touch. That means that AI itself (or a remote attacker, for that matter) can't do things unless I confirm.
if $5.6B is protected by your index finger then you're gonna need kidnap insurance, and a really good pair of gloves.