Arduino GPIO pins have two modes (INPUT or OUTPUT).
When configured as an INPUT, the pin becomes a high impedance (100 Mohms) input)
If you are sensing a push button, the pin MUST be configured as an INPUT, therefore
you can short it directly to 5V or GND without using any power to speak of . What you CAN'T do is connect the push button IN BETWEEN 5V and GND and then push the button because you will short your 5V power supply. Thus, ANY DISCUSSION OF POWER CONSUMPTION OF AN I/O PIN CONFIGURED AS AN INPUT is completely irrelevant and non valid. Such a discussion would only be appropriate for a pin configured as an OUTPUT .
Do you understand the significance of a input impedance of 100 Mohms ?
If you are discussing the power consumption of a 10k ohm pullup resistor, it depends on WHAT you connect that input pin to. By itself , an INPUT pin with a 10k pullup is part of a voltage divider with 10k in the upper position and 100 Mohms in the lower position. Any discussion of input pin power consumption would have to be based on the circuit that you connect to that input pin.