It is recorded in "Sonpi Bunmyaku" (a text compiled in the fourteenth century that records the lineages of the aristocracy) that he resided in Kyoto together with his father Mitsunaga, who was the family head of the Toki clan of Mino-Genji (Minamoto clan), and assumed such titles as Kebiishi Saemon no Jo (third-ranked officer with judicial and police powers in the Left Division of Outer Palace Guards), and when his father sided with the army of the Retired Emperor Goshirakawa in the Battle of Hoju-ji Temple in 1184, he also accompanied his father and fought together in a fierce battle, but he and his father were killed in action and their heads were exposed to the public.
美濃源氏土岐氏の棟梁であった父光長と共に在京し、検非違使、左衛門尉を務めたとされる（『尊卑分脈』）が、寿永2年（1184年）の法住寺合戦で父が後白河院方に加わったため光経もこれに従い、死闘の末に父と共に討ち取られ梟首された。