Though most RC marriage records are on-line, comparatively few records for other denominations are. It would be helpful to know what denomination you think the couple were. Tradition was to marry in the brides church so if she was of a different denomination to her husband that’s where it’s most likely to have taken place.
Moy is in Clonfeacle parish. The early Church of Ireland records were all lost in the 1922 fire in Dublin. RC records start in 1814 and are on-line on the nli site.
http://www.nli.ie
None of the Clonfeacle Presbyterian records start before the 1830s.
Without knowing the parish or denomination it may be difficult to find this marriage. Any additional information you may have would be helpful
Elwyn