SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    48998, 2921, 33177, 33214, 41446, 4386, 
    47009, 5571, 5730, 5418, 4387, 284, 
    47008, 3995, 40539, 36271, 36270, 48320, 
    49408
  )

Query time 0.00133

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 (48998,2921,33177,33214,41446,4386,47009,5571,5730,5418,4387,284,47008,3995,40539,36271,36270,48320,49408)"
        }
      }
    ]
  }
}