If you are importing your database using Phpmyadmin, then there's a configuration file for it:
phpmyadminlibrariesconfig.default.php
Open this configuration file in any editor and change $cfg['ExecTimeLimit'] = 300; to $cfg['ExecTimeLimit'] = 0;
Restart your localhost, now you don't have any time limit.
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Or you can use MySQL command line to import your unzipped SQL file directly, something like below:
mysql -u username -p database_name < my_unzipped_import_file.sql