What sort of SCT-013 do you have? You need the -000 variant. If you have any other, all of which have an internal burden resistor, then you’re in trouble.
The current transformer (without a burden) will drive whatever voltage is necessary to get the current it wants in the secondary circuit, in your case 150 μA. At that level of current for a 100 A device, you won’t have any accuracy to speak of, but that doesn’t concern you. I’d then connect that - without a burden resistor - straight into the base of an npn transistor (with another silicon diode in inverse parallel with the base-emitter junction to protect it from reverse voltage) and then use that into a digital input. Almost any small-signal transistor and diode should be fine.
Something like this:
That’s only a simulation, but it looks OK. The digital input (DI) will be high with no current, and pulses at mains frequency when there is current. It might actually be too sensitive, in which case add a burden resistor in parallel with the diode. The value will be a matter of trial and error, start with a high value and reduce the value until you get a solid high input with no current flowing, and good pulses with the normal current.