I doubt your physical keyboard's connection to the motherboard is encrypted (I'd guess USB, I2C or maybe even PS/2 internally). I would also not be surprised if you can get small in-line sniffers that an attacker, with physical access for half an hour, could hide in your laptop.
All bets are off if your attacker is determined and has physical access.
There have been papers about extracting key presses from acceleration sensors of a phone, or from the sounds of key clicking by statistical inference what feels like a decade ago. You probably don't even need to touch the laptop to do that.
All bets are off if your attacker is determined and has physical access.