Which schematic should I use with CNY 70?
The resistor in series with the opto's LED can be on either side of the LED, with no effect on the operation of the circuit.

In the first circuit, MCUPIN will be high when the LED is on.

The second circuit will also pull MCUPIN high when the LED is on, but there will be an extra 0.7 volt drop due to the extra transistor.

The third circuit will pull MCUPIN low when the LED is on.

In my opinion, the extra transistor is unneccessary (unless you need the inversion of circuit 3), as the opto should be able to drive an MCU input directly.