Possibly Mihail Pivert, but the sources claim he was active during the first quarter of the 19th century. Andrei Kovalsky's working period was 1821-1856 (1856 on your spoon). However, 1856 is not exactly "first quarter", but...?
Found an other possibility, Maksim Funtikov 1840-1900 because the mark looks not only as MP but also like МФ (Latin MF). He fits better than Pivert with the Kovalsky. In addition, Funtikov made spoons.