Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quant-ōcĭus, adv. [quanto-ocius], the sooner the better, as quickly as possible (post-class.): ut quantocius ad ea perveniat oratio, Mamert. Grat. Act. ad Julian. 2: discede quantocius, ne, Sulp. Sev. Dial. 3, 4; Licin. ap. Lact. Mort. Pers. 48, 10; Vulg. Gen. 45, 19.