SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    20482, 20543, 20496, 20495, 20492, 20489, 
    20498, 20497, 20540, 20541, 20542, 
    20491, 20422, 20493, 20480, 20483, 
    20467, 20477, 20511, 20494, 20499, 
    20234, 20272, 20479
  )

Query time 0.00121

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": 24,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (20482,20543,20496,20495,20492,20489,20498,20497,20540,20541,20542,20491,20422,20493,20480,20483,20467,20477,20511,20494,20499,20234,20272,20479)"
    }
  }
}