The register that we see online was copied from the original register which was in a very bad condition so there are errors.
I have found that John Kearney and Elizabeth/ Betty/Eliza/Bess Fitzgerald had several children baptised in Bansha as did a James Kearney and Brid Fitzgerald.
There is a Margaret daughter of J Kearney & Betty Fitzgerald baptised 14 May 1822 suggesting that John Kearney and Elizabeth Fitzgerald were married before the register of marriages began on the 1st January 1822.
I had a look at surrounding parishes with earlier start dates and found no matching marriage.
There is an illegible stone along with a William Kearney in Killadriffe Cemetery which maybe of interest. https://billiongraves.com/grave/William-Kearney/7460416