Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Jakarta to Malawi as you normally would.
CGK and LLW are unique codes to identify airports used in the aviation industry. They are defined by IATA (International Air Transport Association) and are commonly called IATA codes. CGK to LLW refers to a flight route from Jakarta Soekarno-Hatta Intl Airport to Lilongwe Intl Airport. Blantyre Chileka Airport (BLZ), Chelinda Airport (CEH) are other airports near this flight route and their unique identifiers/IATA codes.