3 second door lock warning
 

I have a 2010 K 1500 regular cab. I usually keep the keys on the seat when I park the truck in my garage. I locked my keys in cab when the automatic door lock chimed for a whole 3 seconds before the doors locked the first time I got out of the truck. It surely does not give enough time to get back to truck! Now I am really afraid it will happen sometime when I am out. The manual does not mention that I can cancel out the automatic lock on the regular cab. Is there a way??? I don't understand why chevy truck figured a 3 second warning before the doors lock is sufficient. I can not rely on my memory to check the door lock switch every time before getting out.