SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    23455, 23456, 23457, 23458, 23459, 23460, 
    23461, 23462, 23463, 23464, 23465, 
    23466, 23467, 23468, 23469, 23470
  )

Query time 0.00034

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": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (23455,23456,23457,23458,23459,23460,23461,23462,23463,23464,23465,23466,23467,23468,23469,23470)"
    }
  }
}