Using fragments of 1851 census that survive for the area, later census records (1901 & 1911), vital records, Will extracts & newspaper extracts here's an incomplete tree (I didn't follow up all younger generation).
Daniel McKay (c1782-23 June 1868), farmer, m. Nancy (c1783-1851/1868)
http://www.searchforancestors.com/locality/ireland/census1851/tickmacrevan.html9 Glenarm Tobermore St Townland, Tickmacrevan County Antrim (1851)
Daniel Mckay, Head, Married 65, Farmer, County Antrim Married
Nancy Mckay, Wife, Married 68, None, County Antrim Married
Alexander Mckay, Son, Unmarried, 31, Farmer, County Antrim Married
Letters of Administration of the personal estate of Daniel M'Kay late of Glenarm County Antrim Yeoman a Widower deceased who died 23 June 1868 at same place were granted at Belfast to William M'Kay of Glenarm aforesaid the Son and only next of kin of said deceased. Effects under £200Note: Daniel was a widower and only n.o.k. was son William as son Alexander had died previous year.
Son
Alexander McKay (c1820-1867), innkeeper, m. Isabella
The Will of Alexander M'Kay late of Glenarm County Antrim Innkeeper deceased who died 2 July 1867 at same place was proved at Belfast by the oaths of James Lusk (Saddler) and John Cobain (Grocer) both of Glenarm aforesaid two of the Executors. Effects under £3,000. Will dated 29 June 1867 mentions brother William, wife Isabella, niece Susan McKay, nephew Daniel McKay, father Daniel, nieces- Jenny, Nancy, Eliza, Mary, Margaret,
Belfast Newsletter, 12 Aug.1867: The Executors of the late Alexander M'Kay will Sell by Public AUCTION, at the ANTRIM ARMS HOTEL, Glenarm, on TUESDAY, the 20th of August inst., and following days …1861 Belfast Directory- Glenarm:
https://www.lennonwylie.co.uk/PT_EGHKpage601.htm - GLENARM- McCay, Charles, Antrim Arms Hotel. McKay, Alexander, Commercial Hotel. McKay, John, spirit dealer. 1877 directory- Commercial Hotel not listed
Note: marriage to Isabella mentioned in his Will not found (perhaps pre-1845); the nephew & nieces mentions in Will are children of William.