SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    49169, 2917, 38552, 3975, 4373, 23481, 
    36308, 38553, 43651, 3978, 36717, 43650, 
    34678, 3979, 36472, 36471, 36473, 47487, 
    2047
  )

Query time 0.00239

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 19,
          "filtered": 100,
          "index_condition": "cscart_products.product_id in (49169,2917,38552,3975,4373,23481,36308,38553,43651,3978,36717,43650,34678,3979,36472,36471,36473,47487,2047)"
        }
      }
    ]
  }
}