Chess010

If you leave it on trickle charge all the time while we have this virus am sure it will start no problem 

The adapter lead will only work if it is a ctek 5.0 charger I think. It is available on amazon. I goes from battery outside the bonnet and is permanently attached to battery terminals and is a little plug that I leave sitting on the area just below windscreen outside the bonnet. It is not obtrusive .I can recommend this ctek 5.0 charger available on amazon so search for the attachment which is cheap and also the charger

Hi am glad you finally got into car. as I said it is a sudden freeing although i never had need to resort to allen key to aid movement although it would probably have helped me.I said before I got a CTEK charger along with this from amazon. well worth it as now can charge car anytime without need to get into car as this lead is always attached and jus need plug in to CTEK 5.0 charge unit.
if your car is still under warranty I would get in contact with toyota head office- hopefully they can still reply and tell them failed battery and hopefully gain a second one replaced under warranty. but if not get it checked out by local garage and if faulty there is usually a 3 ,4 or even 5 year warranty from the battery manufacturers and contact them to get their response. -worth doing a check on battery even if  seems to be holding charge
CTEK Indicator eyelet M8: practical LED indicator for immediate indication of battery charge levels
  by CTEK

I found that you just have to keep persevering lubricate by squirting wd40 into lock by letting it dribble down from the key and then keep on wiggling key fractionally clockwise and anti-clockwise it may take 15 or twenty minutes and you think you are getting nowhere but then it suddenly releases. It’s very odd but do not stop keep on trying as described and am sure it will unlock then  charge car.
i have a ctek 5.0 trickle charger along with attached cable available as accessory  that Is permanently connect to battery and the end is sat outside bonnet next to glass and then no need to get into car if battery fails  
let us know how you get on