SELECT 
  product_id 
FROM 
  cscart_wk_reffer_product_status 
WHERE 
  1 
  AND product_id = 312 
  AND status = "off"

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_wk_reffer_product_status",
          "access_type": "ALL",
          "rows": 1,
          "filtered": 100,
          "attached_condition": "cscart_wk_reffer_product_status.product_id = 312 and cscart_wk_reffer_product_status.`status` = 'off'"
        }
      }
    ]
  }
}