I took a picture for you in case you couldn't find the switch.

 

If there is a child in the car, the cops will come and jimmy the door open...hail down a park ranger or dial 911 and explain the situation.

 

@mpatton, Toyota calls that switch on the door a Courtesy Lamp Switch. That should make finding it much easier when you order a new one.

 

We had this happen once (wasn't in our Lexus though). My wife buckled my daughter in her seat, closed the door, and heard the doors lock. She had accidentally left the keys in my daughter's lap and my daughter, of course, started pushing buttons and locked the doors. It was hot and after about 10 minutes we were ready to bust out a window when...I kid you not...some dude in a trench coat walks up, pulls out a slim-jim/jimmy, casually unlocks the door and walks off into the sunset. Whether an angel or criminal, I'm glad he was there.