British sockets have shutters that prevent children from getting a shock
British plugs are considered to be the safest in the world and their shutter mechanism prevents anything from accessing the live wires other than a plug.
If you are using socket protectors, it’s best to remove them
Socket protectors are not made to British safety standards and should not be used. If you are currently using them, it is recommended that you very carefully remove them and speak to an electrician about checking your socket outlets for safety.
If you are still concerned about sockets being accessible, it is only advisable to cover a socket with a closeable lid socket cover over the full socket plate.