This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
琚 combines 王 (jade) with 居, which likely contributes the sound. The exact historical development is uncertain.
The left side is 王 (jade), suggesting a precious stone. The right side 居 looks like a person sitting, but the overall meaning is unclear. Imagine a rare jade ornament whose purpose is forgotten.
For キョ, imagine a Kyoto jeweler holding up a mysterious jade piece: Kyoto -> キョ, and the jade 王 is the centerpiece.