Reddit mentions of Murphy 1/4" x 1" Machinery Eye Bolt, Shoulder, Forged Self Colored Carbon Steel

I'm reading this as there being a code/ elfin-safety requirement that there be a "safety" on the speakers in spite of them being quite lightweight and quite securely mounted.
If this is going to be inspected by someone familiar with entertainment facilities, then random chain screwed in with a washer may not successfully meet the requirements. Chain that is formed by twisting or bending without welding of the links is right out, on fear that in a fire situation the softened metal will unbend.
The right way is detailed here:
http://www.jblpro.com/pub/technote/tn_v1n14.pdf

Now, on to practical details: if that bracket that you show falls off the wall, then the safety on your loudspeaker needs to secure a dynamic load of not just the 2kg speaker but also the 3kg bracket. The rule of thumb for rigging of dynamic loads is multiply the load by 5, and that gives one the required rating of your hardware, assuming that all hardware is used correctly.
For attachment to the speaker itself, the right way is to use a forged shoulder eye bolt, bolted right through a surface of the box, with a big-enough backing plate that it won't pull through with a sharp 25kg tug (it's not the fall that is the problem, it is the sudden stop at the end...) No-one trusts a screw (self tapping or otherwise) in this situation.
Then I would suggest a standard lighting safety cable of appropriate length to lasso the beam and clip to your speaker eye.
On some speakers it is pretty obvious how to remove the woofer so that you can peer in and see where it is safe to drill. You also want to be sure that a sudden tug on the top/back/side face of the box (as appropriate) isn't going to just disconnect that face from the front face which is carrying all the weight of the heavy magnets in the drivers.