Capacitive Touch and implementation with BeagleBone Black
It will take longer for the receive to charge up if the finger is close.  You say that you imagine it would take longer then you state it would be shorter!

The 40K resistor and the sensor form a time constant that dictates how fast the receive line charges up, if the capacitance is higher it will take longer.

The actual amount of capacitance depends upon the sensor size but will typically be a few pF (not 1uF as you show) when a finger is in close proximity to a sensor.

Without the finger there will be parasitic capacitance that depends upon how the sensor is constructed and the length of wire etc but it could easily be 10-20pF even if you minimize those things. This would give  time constant without touching the sensor of 40*10^3*10^-11.  This is about 400s.  With the finger adding 1pF this will increase by about 5% to about 420ns. This is very fast and not much of a change.

As the linked article states you can get higher sensitivity by increasing the value of the resistor to many megohms, this will give 100s of microseconds time constant with larger changes when in proximity, which is easier to distinguish  You also get higher sensitivity by increasing the size of the sensor so you can sense the entire hand rather than just a finger.