Play music in the background, Chew gum, or have some tea right next to me. Maybe also you could try to plan out this amount of time before hand and eliminate distractions like phone and tv then tell people who might talk to you during your time and ask them politely to not bother you during that time.
I have made a workspace that has few visual distractions (clear desk, against a wall so I’m not looking around the room) I place my phone out of reach from my seat and clear all non-work related windows in my computer. I set priorities of things to get done and try to tackle the hardest, followed by something easy, and then something hard. I try to take stretch breaks while still thinking about my work.
I tend to use the pomodoro method, which is essentially where you work for 25 minutes, then take a 5 minute break. After 4 pomodoros (2 hours), you take a longer break (about 30 minutes). I personally find it difficult to stay focused for long periods of time, so I use this method to prevent burnout. I also suggest putting your phone in a place that’s hard to reach so you don’t get distracted by it a easily. You can also write down what distracted you during each “focus session.” I find this very helpful, because you know what needs to change next time so you can focus better. I hope this helps! Have a great day 🙂