This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
虗 is a variant form of 虚, combining 虍 (tiger) with 丘 (hill). The exact historical development is uncertain, but it likely shares the same origin as 虚, expressing emptiness or hollowness.
The outer 虍 suggests a tiger, and the inner 丘 is a hill. Picture a tiger on an empty hill, with nothing around—an image of emptiness.
For キョ, imagine a key opening an empty box: key -> キョ, and the box is as empty as the hill under the tiger.