Double click

Here's the key:

To lock or unlock doors only one press is required.
I keep all my keys in the same pocket, so while I was searching for my home key, the car lights flashed: the unlock button accidentally was pressed by the other keys rolling in the pocket.
Single click is a bad design choice:
single click -> select
double click -> execute
that's the way on my desktop, that should be the way in my pocket too.