SELECT 
  pair_id, 
  v.video_id, 
  video_url_id, 
  source, 
  position 
FROM 
  cscart_videos as v 
  INNER JOIN cscart_videos_links as vl ON v.video_id = vl.video_id 
WHERE 
  object_id = 354 
  AND vl.object_type = 'product' 
ORDER BY 
  position

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "vl",
          "access_type": "system",
          "possible_keys": ["object_id", "video_id"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "v",
          "access_type": "const",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["video_id"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}