Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Indonesia to Malawi as you normally would.
This is defined as Denpasar Bali Ngurah Rai Airport (DPS) and Lilongwe Intl Airport (LLW). Codes like Lilongwe Intl Airport are often used to just call airports uniquely. Blantyre Chileka Airport (BLZ), Chelinda Airport (CEH) are other airports near this flight route and their unique identifiers/IATA codes.