Exterior door mounting plate - replacing door hardware
There are two reasons for these products - security and appearance. For security, you typically want something that also covers the gap between the edge of the door and the door frame, to prevent jimmying the lock, or something that covers front, back and side of the door to make it harder to get to the lock mechanism. But for appearance, all you need is a flat plate with holes in the right places.

Most of the products I found in a quick search with predrilled holes appear to be much shorter. If you can't find an exact match (holes in the right places and long enough to cover the desired area), get a plain plate:

and use a hole saw to drill holes where needed.