Mysql Query takes more than 300 seconds - mysql

Question

I have two MYSQL tables, A and B. Table A has 44,902 rows and table B has 109,583 rows.
I would like to compare two columns from the two tables and return the rows from table A where it finds a match. My, unsuccessful queries are:
SELECT pool.domain_name FROM `pool`, `en_dict` WHERE pool.domain_string = en_dict.word
and another variant:
SELECT a.domain_name FROM `pool` as a inner join en_dict as b on a.domain_string = b.word
both solutions falied returning any values under 300 seconds.
What should I do to reduce the time for finding the matches??
P.S. I have tried adding a LIMIT at the end of the queries and managed to display 10 results in 245 seconds.
Edit: My tables structures are as follows :
--
-- Table structure for table `en_dict`
--
CREATE TABLE `en_dict` (
`word_id` bigint(20) unsigned zerofill NOT NULL AUTO_INCREMENT,
`word` varchar(35) NOT NULL,
PRIMARY KEY (`word_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=109584 ;
-- --------------------------------------------------------
--
-- Table structure for table `pool`
--
CREATE TABLE `pool` (
`domain_id` bigint(20) unsigned zerofill NOT NULL AUTO_INCREMENT,
`domain_name` varchar(100) NOT NULL,
`domain_tld` varchar(10) NOT NULL,
`domain_string` varchar(90) NOT NULL,
`domain_lenght` int(2) NOT NULL,
`domain_expiretime` date NOT NULL,
PRIMARY KEY (`domain_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=44903 ;

Answer 1

Try adding an index on the relevant columns of your tables:
ALTER TABLE `pool` ADD INDEX `domain_string_idx` (`domain_string`);
ALTER TABLE `en_dict` ADD INDEX `word_idx` (`word`);