Mor/Ryde has a locking TV mount and we have one in the bedroom. It's very well made and has a handle at the bottom that you pull down. Our KZ TT has a mount that you have to push against the wall to lock it in place and give it a tug to unlock it. Don't particularly like it and don't know the brand.
I've seen some TT manufacturers use an ordinary articulating mount and secure it in place with Velcro straps for travelling. I did this on a previous TT. You can just use a fender washer & screw to attach the Velrco to the wall. I used plastic clips from
theclip.com and you can go to a shoe store to get the Velcro sewed together at the clip end.