Contact the people who sold you the house.
If the keylock is in the "handle" part, and the handle part comes off, you might be able to get some new handles. Or see if any of your neighbours have the same kind and ask if you can borrow a key.
However, the cheaper way, if you think it might be the same brand, photograph the part, and send the pic, and all the numbers you can see, to the makers, and ask if they can provide spare keys.