A sarcophagus (plural sarcophagi) was a type of coffin used by the ancient Egyptians.
The stylised technology of the Osirian lodestone had the appearance of an ancient Egyptian coffin. There were also others that stored the Osirian service robot, who appeared as mummies. (TV: Pyramids of Mars)
A sarcophagus with an electronic lock was stored on board the space-faring version of the Orient Express as a means of capturing a mummy known as the Foretold. However, it was never put to use beyond accidentally being opened by feedback from the Twelfth Doctor's sonic screwdriver, as he later found away to help the Foretold pass on when alien technology kept his body from dissolving until it registered that a long-ended war was over. (TV: Mummy on the Orient Express)
Anwar Nazir, the leader of the Cult of the Black Pyramid, journeyed to the resting place of Horus to awaken the ancient being. However, he discovered that Horus had died after a failure in his sarcophagus's life support system. (PROSE: Scarab of Death)