Yes, use several series resistors, some 1206 resistors are only rated to 50V. You need to have enough to make it at least 310V plus extra for safety margin. I would also consider dropping the total resistance to no more than 100K to allow more LED current to flow.
A better solution is to use several resistors, choose values so the peak current is adequate for the LED, but wire the LED across a bridge of four diodes. If you connect the bridge at the LED side of the resistors, the voltage will be very low so you can use cheap silicon signal diodes (1N914 for example) but the transistor will then be made to conduct on both positive and negative AC cycles so you can also reduce the time constant of R8/C4 to make the circuit react faster to AC presence. For example drop C4 to 1uF.
Brian.