How can I tell which fuses are set on an ATtiny?
This seems to be an X -> Y problem, with X being the missing clock source on your ATTiny, which prevents communication.

If you have a second Uno or other AVR device, you can use that to generate a clock signal on any of the digital pins:

void setup() {
  DDRB = 0b00100000;  
}

void loop() {
  PINB = 0b00100000;
}


This creates a square(~ish) signal on Pin 13 with a frequency of 1.6 MHz.
Depending on the IDEs optimization level (platform.txt), a frequency of 4 MHz is also achievable (at -O3 instead of -Os).

Connecting this to the XTAL1 pin of your ATTiny85 should allow you to communicate with the board.
Make sure to interconnect all grounds.