The Catholic parish of St. Nicholas covered parts of a number of Civil and Church of Ireland parishes - including both St. Nicholas Within and St. Nicholas Without, along with St. Luke's, St. Kevin's, St. Patrick's, parts of St. Peter's etc. The Catholic parish church was located on Francis Street, and there is still a church at the same location which is dedicated to St.Nicholas of Myra.
The early baptism records do not include detailed residences so unless Laurence snr. had an occuaption or trade that might be included in a directory there would probably be no way to establish an exact address for them.
I found some additional baptisms for children of Laurence Markey snr, and Esther/Esst Quinn - in St. Pauls Catholic parish, on the north side of the city, I'll put together the details an reply here ..