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.
Different people/cultures/countries/crafts all use different names for that TYPE of key. I call it a hollow barrel cabinet key, which is as good a type name as any.
People who are experienced with various types of locks and keys, e.g. picking locks, cutting and crafting keys, rekeying locks etc., know that what you ask is not as simple as you may think. The picture below shows the TYPE of key you need but the size and location of the tooth at the end, along with the number and size of the slot(s) cut into the tooth, are what determine whether or not it will open the lock. There are literally hundreds (thousands?) of possible configurations...
