How to disable GNOME keyring?

I think you just disabled the auto-unlock. To disable it completely, I suppose you could uninstall it. If that makes the package manager unhappy, you could also sudo chmod -x /usr/bin/gnome-keyring

Try this: System ⇒ Preferences ⇒ Startup Applications and uncheck gnome-keyring-daemon.

For Gnome 3 (ubuntu 17.10 and later):