Adding a MySQL Index to a column/s using Symfony3 and XML

I have the following XML file in Symfony3 and I would like to add a MYSQL index to the column videoPublisherDate as I will be querying it quite a bit and ordering based upon it. I can add it manually via PHPMYADMIN but I was wondering how a can update the xml below so that it can be done automatically.

Thanks

<?xml version="1.0" encoding="utf-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
  <entity name="AppBundle\Entity\Videos" table="videos">
    <unique-constraints>
        <unique-constraint columns="video_id" name="search_idx_videos" />
    </unique-constraints>
    <id name="id" type="integer" column="id">
      <generator strategy="IDENTITY"/>
    </id>
    <field name="videoSource" type="text" column="video_source" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoId" type="string" column="video_id" length="50" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoTitle" type="text" column="video_title" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoImage" type="text" column="video_image" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoPublisher" type="text" column="video_publisher" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoPublisherId" type="text" column="video_publisher_id" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoPublisherDate" type="text" column="video_publisher_date" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
    <field name="videoLength" type="integer" column="video_length" nullable="false">
      <options>
        <option name="unsigned"/>
      </options>
    </field>
    <field name="videoActive" type="integer" column="video_active" nullable="false">
      <options>
        <option name="unsigned"/>
        <option name="default">1</option>
      </options>
    </field>
    <field name="videoTags" type="text" column="video_tags" length="65535" nullable="false">
      <options>
        <option name="fixed"/>
      </options>
    </field>
  </entity>
</doctrine-mapping>