Index: src/wp-admin/includes/upgrade.php
===================================================================
--- src/wp-admin/includes/upgrade.php	(revision 32458)
+++ src/wp-admin/includes/upgrade.php	(working copy)
@@ -527,7 +527,7 @@
 	// Don't harsh my mellow. upgrade_430() must be called before
 	// upgrade_420() to catch bad comments prior to any auto-expansion of
 	// MySQL column widths.
-	if ( $wp_current_db_version < 32364 )
+	if ( $wp_current_db_version < 32453 )
 		upgrade_430();
 
 	if ( $wp_current_db_version < 31351 )
@@ -1449,6 +1449,10 @@
 function upgrade_430() {
 	global $wp_current_db_version, $wpdb;
 
+	if ( $wp_current_db_version < 32453 ) {
+		$wpdb->query( "ALTER TABLE $wpdb->posts ADD INDEX type_mime(post_type,post_mime_type)" );
+	}
+
 	if ( $wp_current_db_version < 32364 ) {
 		$content_length = $wpdb->get_col_length( $wpdb->comments, 'comment_content' );