MySQL query optimization using where statement -

i working on big data base contains >1 million records, using below query full out records based on criteria slow though index primary key.

sql:

select distinct title, productid, catid, description, producturl,      regularprice, saleprice, imageurl, merid, created_at,      updated_at, name, link, source  products p, advertisers  (title '%headphone%' or description '%headphone%')  , catid=22  , regularprice not null  , p.merid = a.advertid 

can me on how optimize query?

thanks,

edit:

table structures:

create table `products` (   `id` int(10) unsigned not null auto_increment primary key,   `productid` varchar(50) collate utf8_unicode_ci not null unique,   `catid` varchar(50) collate utf8_unicode_ci not null,   `title` text collate utf8_unicode_ci,   `description` longtext collate utf8_unicode_ci,   `producturl` text collate utf8_unicode_ci not null,   `regularprice` double(8,2) default null,   `saleprice` double(8,2) not null,   `imageurl` text collate utf8_unicode_ci not null,   `merid` varchar(50) collate utf8_unicode_ci not null unique,   `created_at` timestamp not null default current_timestamp,   `updated_at` timestamp not null default current_timestamp ) engine=innodb default charset=utf8 collate=utf8_unicode_ci;  create table `advertisers` (   `id` int(10) unsigned not null primary key,   `advertid` varchar(50) collate utf8_unicode_ci not null unique,   `name` text collate utf8_unicode_ci not null,   `link` text collate utf8_unicode_ci not null,   `logo` text collate utf8_unicode_ci not null,   `source` varchar(10) collate utf8_unicode_ci not null ) engine=innodb default charset=utf8 collate=utf8_unicode_ci; 

explain:

mysql> explain extended select distinct title, productid, catid, description, producturl, regularprice, saleprice, imageurl, merid, created_at, updated_at, name, link, source products p, advertisers (title '%headphone%' or description '%headphone%') , catid=22 , regularprice not null , p.merid = a.advertid; +----+-------------+-------+------------+--------+---------------------+----------+---------+-------------------+--------+----------+------------------------------+ | id | select_type | table | partitions | type   | possible_keys       | key      | key_len | ref               | rows   | filtered |                        | +----+-------------+-------+------------+--------+---------------------+----------+---------+-------------------+--------+----------+------------------------------+ |  1 | simple      | p     | null       |    | merid               | null     | null    | null              | 682242 |     1.89 | using where; using temporary | |  1 | simple      |     | null       | eq_ref | advertid,advertid_2 | advertid | 152     | datafeeds.p.merid |      1 |   100.00 | null                         | +----+-------------+-------+------------+--------+---------------------+----------+---------+-------------------+--------+----------+------------------------------+ 2 rows in set, 2 warnings (0.00 sec) 

check index in join key merid products , advertid advertisers

 select distinct      title   , productid   , catid   , description   , producturl   , regularprice   , saleprice   , imageurl   , merid   , created_at   , updated_at   , name   , link   , source  products p inner join  advertisers  on p.merid = a.advertid (title '%headphone%' or description '%headphone%')  , catid=22  , regularprice not null  

coulb useful composite index on (probably ) more selective columns column

 (catid, merid) 

regularprice, title , description due use of , si not null don't should useful in composite index