Some people said my question didnt give enough details.In all fairness I will be a little broader.?

The cops stopped me for riding the line. He asked me if I had been drinking.I said no.He said I smelled like alcohol and hancuffed me. He looked with his flashlight and asked me what was in the lockbox. I said I dont know.He then opened it with a key without asking. California law says when transporting a firearm it must be in a lockbox or trunk.I was breathalized after and blew a .04.I thought cops couldnt open anything locked. I have been stopped before and the officer ALWAYS ask if he can search my vehicle. I ask again by law was this lawful?