its worth trying the rear hatch with the spare key next
and if that won't open then I'd suggest to try and get some battery power into the car as its likely a low battery voltage is the 1st reason why it locked in the 1st place
As you can't get into the car/ boot the other way to do this is jack the car up so you can get under the front.
Locate the starter motor and the large power cable that runs to it - connect the positive battery charger lead to this terminal
then connect the charger negative lead to the metal of the engine block
This should complete the charging circuit and get some power into the battery allowing you into the car