SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fef14338266e6444a1cf147235979dbfcca5808d97e3b00dc916a9a49407b141' 
  AND token = 'XdcgnOfkTQHMQsZZov+/z16mxTv7UCD8lIJr64uodFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}