Can I put truck in neutral and tow it without a key
You would need to disconnect the transmission linkage on the side of the transmission. If you are planning on flat towing it, you will have an issue with the steering wheel being locked.
I would not tow it in nuetral if its a automatic and the rear wheels touching the ground . Instead tow it from the rear i use to do wrecker service and several people did tow there vehicle like this and later i was towing them back home