It sounds like a duel boot LibraELEC / Android system.
If so it's booted into LibraELEC (or OpenELEC if its older)
In which case in Kodi, go to Programs, LibraELEC (OpenELEC) Configuration, scroll to the bottom of the main page and click on Reboot into android.
If that's not the case you need to enter the reset stage of your firmware. I'm unsure on your box, but usually you have to use a paper click or toothpick and push and hold it whilst a reboot is done in the Reset hole on the back of the box.
Once in this mode choose reboot to android, or if all else fails, Factory Reset.