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 (
    21085, 21086, 21087, 21088, 21089, 21090, 
    21091, 21092, 21093, 21094, 21095, 
    21096, 21097, 21098, 21099, 21100
  ) 
  AND cscart_seo_names.type = "p" 
  AND cscart_seo_names.dispatch = "" 
  AND cscart_seo_names.lang_code = 'ru'

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "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 (21085,21086,21087,21088,21089,21090,21091,21092,21093,21094,21095,21096,21097,21098,21099,21100) and cscart_seo_names.`type` = 'p' and cscart_seo_names.dispatch = '' and cscart_seo_names.lang_code = 'ru'"
    }
  }
}