SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    9877, 9894, 9891, 10480, 9893, 9878, 
    9886, 9882, 9888, 10482, 13091, 12551, 
    12638, 12634, 12636, 12635, 12599, 
    12627, 12600, 12639
  )

Query time 0.00080

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (9877,9894,9891,10480,9893,9878,9886,9882,9888,10482,13091,12551,12638,12634,12636,12635,12599,12627,12600,12639)"
    }
  }
}