Power door lock eventually will fail.
You can buy an actuator assembly from Toyota dealer ( about $200 ). It's just 1 small motor connected to a wire cable.
Just open the door panel, only 3 or 4 screws, unplug the old assembly, remove a few screws and plug the new one in. Pretty easy. All Toyotas and Lexus have the same design for lock actuators, just different cable lengths.
Another cheaper fix is to buy the little DC motor ($5) in eBay, about the size of a match box, and replace it. You need a little $10 hand tool to press the motor shaft out of the wire cable. You tube has all kinds of videos about replacing either the assembly or the motor.