Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Kuala Lumpur to Grenada as you normally would.
This is defined as Kuala Lumpur Intl Airport (KUL) and St. George's Point Saline Intl Airport (GND). Codes like St. George's Point Saline Intl Airport are often used to just call airports uniquely. Ready for more IATA code knowledge? These are related airports for your current travel destination: Kuala Lumpur Subang Airport (SZB), Malacca Batu Berendum Airport (MKZ).