create table track (
  ip int,
  index ip_index (ip));

create table countries (
  ipfrom int not null,
  ipto int not null,
  index from_to_index (ipfrom, ipto));
  
insert into track () values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10);

insert into countries (ipfrom, ipto) values (1, 10), (2, 9), (3, 8), (4, 7), (5, 6);

explain select * from track t, countries c where t.ip >= c.ipfrom and t.ip <= c.ipto;

drop table track, countries;

create table track (
  ip int,
  index ip_index (ip));

create table countries (
  ipfrom int not null,
  ipto int not null,
  country char(2) not null,
  index from_to_index (ipfrom, ipto));

insert into track () values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10);

insert into countries (ipfrom, ipto) values (1, 10), (2, 9), (3, 8), (4, 7), (5, 6);

explain select * from track t, countries c where t.ip >= c.ipfrom and t.ip <= c.ipto;