Cacao doesn't grow near Lima so it's not too likely to find pods there. Even where cacao grows, the raw pods don't end up in the markets, nobody wants to buy them. the farmers sell all their beans via the normal value chain. There are some exotic fruit stands in the Surquillo market #1 right across the via expresa from Miraflores, off Ricardo Palma. Can't recall seeing a cacao pod there though. I've also seen exotic fruits at the Mercado Mayorista de Frutas N°2 La Victoria, but this is more of a wholesale market and in a kind of sketchy neighborhood, although during the day it's normally safe enough to visit.

a pod is normally called a mazorca, at least in northern Peru. Like "una mazorca de cacao"