Just found som infocontaining the name Keay and possible origins.
KAY, KEY, KIE, KEE, contraaed from Mac Aedha, 'Aedh's son.'
'Cucail MAC AEDHA,' A.D. 1098.* 'AE ' DH, (ay, pronounced like the ay in say), genitive AEDHA, is interpreted by Cormac Mac Cullenan, Colgan and other writers, to mean fire . . . . This name has been in use in Ireland from the most remote antiquity . . . . It was the name of a great many of our ancient kings; and the Irish ecclesiastics named AEDH are almost innumerable . . . . The usual modernised form of Mac Aedka is MAGEE, which is correct, or McGEE not so correct, or MAC KAY, which would be correct if it were accentuated on the last syllable, which it generally is not.
The form KEE may possibly be a contractlon of Mac Caoch, the dimsighted (man's) son.'