– In app/etc/di.xml file locate

<preference for="Magento\Framework\DB\LoggerInterface" type="Magento\Framework\DB\Logger\Quiet"/>

and change it to

<preference for="Magento\Framework\DB\LoggerInterface" type="Magento\Framework\DB\Logger\File"/>

– Pass constructor arguments like below. Check Magento\Framework\DB\Logger\File for more configuration options.

<type name="Magento\Framework\DB\Logger\File">
    <arguments>
        <argument name="logAllQueries" xsi:type="boolean">true</argument>
        <argument name="debugFile" xsi:type="string">query.log</argument>
    </arguments>
</type>

– Find log files under var directory