This is available now with a new release of the pylance extension (which I assume most people using python in VS Code will have).

It should be noted that the optimizeImports with the ctrl + alt/option + o keybinding only sorts and does not remove unused imports (see github issue).

I have autosave in place, so I prefer a keyboard shortcut. If you have the pylance extension, you can add the following to your keybindings.json

    {
        "key": "shift+alt+r",
        "command": "editor.action.codeAction",
        "args": {
            "kind": "source.unusedImports",
        }
    }

You can change the key binding to be whatever you want, but basically when you press the keybinding (i.e shift + option/alt + r) it should remove all your unused imports.

I believe if you wanted this automatically on save as above you could add the following into your settings.json:

    "[python]": {
        "editor.codeActionsOnSave": {
          "source.organizeImports": "explicit",
          "source.unusedImports": "explicit",
        }
    }

There are two because the Python extension created the Sort Imports command before VS Code introduced the Organize Imports command. So the Sort Imports command is the more "official" one for now.

There is an open issue, though, to transition over to Organize Imports at some point. Feel free to the issue if you would like to help bump its priority.