Those locks nearly always have multiple wafers/levers/tumblers that match specific notches that are cut into the key; these are not visible from the outside.
So even though the necessary key profile is discernible in the pictures, there is no way to tell what particular key cut will work. If it was so easy then the lock would be pointless as anybody could just look at it and produce a key.
You need a locksmith. Alternatively, someone who is good at picking locks could perhaps get the chest open, then you could remove and replace the lock with a new one.