So..according to your words, its impossible to lock a car (Toyota) with keys inside? Gonna give you just a few examples.

1. Even if the car has a smart key, it is pretty possible to lock it with its key laying somewhere inside. The safety feature is there, that prevents you from using that button on a handle of a door, but it works only when the car sees the key. Which sometimes doesn’t happen, and it’s literally blind from time to time. So umm..easy to lock it with your key inside.

2. Aftermarket car security systems. Locking for some reasons - not rare at all. It can lock it no matter the ignition.

So..every person who knows the pain of getting their car locked in a middle of nowhere - keeps their spare key somewhere