SearchOrder queue of orders to prepare

Questions
1

Hi, I have a search order query prepared but I want to make sure its correct. For a restaurant, what is the proper way to get for the current day, all orders that have been paid for and employees should be preparing, sorted by create date. Is the below the correct query to do that? Another question, if I have pickup or delivery fulfillments, how do I sort orders by the time they should be made, not just the time the order was created.

query: {
  filter: {
    date_time_filter: {
      created_at: {
        start_at: --BEGINNING OF DAY--,
        end_at: --END OF DAY--,
      }
    },
    state_filter: { 
      states: [
        "OPEN"
      ]
    }
  },
  sort: {
    sort_field: "CREATED_AT",
    sort_order: "ASC"
  }
}

Thanks!