Freezing/locking a camera's transformations so it can't be moved

Hi All,
Apologies in advance if this is an obvious answer, but I am currently using a camera actor in one of my viewports (locked the viewport to the camera) to reference a concept piece I am working from, I was wondering if it is possible to lock the camera so it cant be moved. I keep accidentally going to fly around the scene in the viewport that is locked to camera while forgetting to switch back to another viewport, resulting in the camera then being wrong.

Thanks for your time in advance
Kind regards