Following works in gawk

$ echo | awk -F. '{print $1 == 0 && $2 >= 7}'
0

however the same fails in busybox's awk

$ echo | busybox awk -F. '{print $1 == 0 && $2 >= 7}'
awk: cmd. line:1: Unexpected token

My understanding of https://pubs.opengroup.org/onlinepubs/009695399/utilities/awk.html#tag_04_06_13_16 is that the parentheses are optional there. When you add them, it starts to work:

$ echo | busybox awk -F. '{print ($1 == 0) && ($2 >= 7)}'
0