No chance you will get the full state pension unfortunately. Opting out of Serps used to mean that the money you would have paid into Serps went into your private pension. In a way it was a swings and roundabouts agreement, you get less state pension but your private pension should prosper more. It was called contracting out but I think that it ceased being an option a few years ago but I may be wrong. The rules are so complex though and change from time to time. Until I delved into it I actually didn't even know my company pension had contracted out decades ago. I had no say in it at all. Like most people you just do your job and enjoy life, a pension is for old people until all of a sudden you realise that is you lol.
A better company/private pension is probably wise though. It is the only chance you have of retiring early. If you have to wait for the state pension you are looking at at least 67 now I think depending on your age. I would look at your private pension and savings providing the luxuries in life and your state one covering the basics, such as utility bills and food. With a mortgage paid off most people should cope okay unless they have very expensive hobbies or addictions.
I was fed up with working long shifts, travel and the stress of working. One day I sat down and worked out what I was working for aside from the basics. Two holidays a year, going to the match and odd nights out. I realised if I took early retirement I could stil do this so finishing work was a no brainer. Yes it meant dipping into my savings for the holidays and any other luxuries but this was only until my state pension kicks in, then I have that added. My decision was swayed by seeing around ten people in the company die before the age of sixty. All these were working towards this utopia of a relaxed enjoyable retirement but never reached it. If this covid situation has taught us anything it's nothing is guaranteed in life. Now even those nights in the pub, holidays abroad and going to the match are gone, so you could be earning 100 grand a year but there is nothing to spend it on. Live it now and live it fast. While it's sensible to have one eye on the future don't make that at the expense of enjoying the moment.