SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    19885, 19886, 19887, 19888, 19889, 19890, 
    19891, 19892, 19893, 19894, 19895, 
    19896, 19897, 19898, 19899, 19900
  )

Query time 0.00036

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 (19885,19886,19887,19888,19889,19890,19891,19892,19893,19894,19895,19896,19897,19898,19899,19900)"
    }
  }
}