in softcam.key file @ the bottom:
"P 1015FFFF 01 42081F4F53BF81 ; added by Emu Tue Nov 5 18:42:08 2019 UA: 0062FE09"
"0062FE09" is the first digits of the EMM key was used.
sometimes you'll see another EMM (if you have more then 1EMM key), for the same channel as they are being changed by the provider(ex. 58w3720V).