Getting API response with minimum latency

javascript

Given an API - /all_data which returns all the schools, all the students and all the books from DB. And return the reponse with minimum possible latency. 
And if any of the query fails, returns balnk array for only that entity.
Example - 

router.get("/all_data", async (req,res,next)=>{
  let schools = await School.find(); // takes 300ms to complete
  let students = await Student.find();  // takes 300ms to complete
  let books = await Book.find(); // takes 300ms to complete


  return res.json({
    schools: schools,
    students: students,
    books: books
  });
})

Problem with this code is that this request is taking 900ms right now to respond. Also if any of the query fails, we do not get any data. 

We want to handle the erro such that (for example) if books query fails we should be sending - 
{
schools: schools,
studenmts: students,
books: []
}