Disable power button menu and volume keys when screen is locked

Hi,
I installed an anti-theft tracking app on my phone but I can't disable the "airplane mode, sound, reboot, shutdown" menu (that appears when you long-press the power button) and the volume rocker, when the device is locked but the screen is on... so anyone can just shutdown my phone or mute the ringtone or put it in airplane mode and that makes the tracking app useless.

I tried using "Smart lockscreen protector" by nez droid but it doesn't work.

Is there a way to disable these "features"?


Thanks

Edit:
I have root and bootloader unlocked if this helps