SELECT 
  cscart_seo_names.object_id AS product_id, 
  cscart_seo_names.name AS seo_name, 
  cscart_seo_names.path AS seo_path 
FROM 
  cscart_seo_names 
WHERE 
  cscart_seo_names.object_id IN (
    321, 320, 319, 318, 317, 316, 315, 314, 
    313, 312, 311, 310, 309, 308, 307, 306
  ) 
  AND cscart_seo_names.type = "p" 
  AND cscart_seo_names.dispatch = "" 
  AND cscart_seo_names.lang_code = 'en'

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_seo_names",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "dispatch"],
          "key": "PRIMARY",
          "key_length": "206",
          "used_key_parts": ["object_id", "type", "dispatch", "lang_code"],
          "rows": 16,
          "filtered": 100,
          "index_condition": "cscart_seo_names.object_id in (321,320,319,318,317,316,315,314,313,312,311,310,309,308,307,306) and cscart_seo_names.`type` = 'p' and cscart_seo_names.dispatch = '' and cscart_seo_names.lang_code = 'en'"
        }
      }
    ]
  }
}