Some smart sockets come with a child-lock (software) switch which disables the switch being turned on/off via the hardware button. Not sure whether it’s enough for you.
Often enough, and ideally, appliance outlets are “hidden” or readily inaccessible. But there are also enough situations where that’s not the case. And smart outlets come in different styles: ones that plug into a standard wall outlet, or a full replacement for a standard wall outlet unit. The integration of each type comes into play as well.
You could always use an extension cord.
I believe the only option for you then is an in wall switch.
If there is not enough room behind the outlet then you could get a frame that extends the outlet from the wall.