You're probably not going to get a special key into a locked gun in the dark. The special internal locks satisfy laws, not reality or necessity.
Internal locks are like airport security. They're there to make you feel safe when you really aren't. Actually, it's there to make people who don't understand the particulars of safety and firearms to feel better.
If you have kids, you should probably get a gun safe, even a small one. A firearm that doesn't shoot is just a rock to throw. A safe that you can open quickly, but has a useful firearm inside is thoughtful planning.
I live alone, but my firearms are loaded and ready to fire. When I visit, my firearm gets unloaded, with the safety on, so small hands can't do anything bad. When children visit my house, guns are locked up. Even my bedroom door has a key lock, just so that no tragedies can occur.