I have a table
(id, location, timestamp, type, value)

location / timestamp / type can duplicate,   
but location + timestamp + type is unique

---

1, "Paris", 1474986000, "a", "100"   

2, "London", 1474986000, "a", "90"   

3, "Paris", 1474986000, "b", "12"   

4, "London", 1474986000, "b", "13"   

5, "Paris", 1474990000, "a", "100"   

6, "London", 1474990000, "a", "100"   

7, "Paris", 1474990000, "a", "100"   

8, "London", 1474990000, "a", "100"

---

I tried to check existed before insert using select statement, but i have >100000 record, it spend a lot of time for checking

any other solution can solve this problem? thanks~