Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Columbus Airport to Ocho Rios as you normally would.
Located just 8.9 mi from the city center, Ocho Rios Boscobel is the airport most travelers will use when flying to Ocho Rios from Columbus. Booking flights from Columbus to Boscobel (OCJ) should be relatively easy as there are 0 daily inbound flights from Columbus from 0 different airlines.
This is defined as Columbus Airport (CMH) and Ocho Rios Boscobel Airport (OCJ). Codes like Ocho Rios Boscobel Airport are often used to just call airports uniquely.