Your open door policy is quietly destroying your daily productivity. When you allow staff to interrupt you every five minutes with a minor complaint about the copy machine, you will never actually finish your state licensing paperwork or process your payroll accurately.
You need to implement radical time blocking. Block off two specific hours every Tuesday and Thursday morning. Close your office door, put a physical sign on it that clearly says "Do Not Disturb," and turn off your phone notifications completely. Train your staff that unless a child is actively bleeding or the building is physically on fire, they must wait until your block is officially over. It will feel uncomfortable the first few weeks. Your team will hover outside your door and shuffle their feet. Push through it. Once you train your team to respect your focused work time, you will accomplish more in those four weekly hours than you previously managed in an entire fragmented workday.