SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1838, 1938, 1830, 1514, 1835, 1678, 1693, 
    1711, 1699, 1698, 1869, 1834
  )

Query time 0.00089

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1838,1938,1830,1514,1835,1678,1693,1711,1699,1698,1869,1834)"
    }
  }
}