SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e18bd2132c413c2b7feafd83af56953186c32cc1d6bce098f30aa3ab79716fa7' 
  AND token = 'xZ7NnptDKJq1kh9ToT8//dMeWHkWHq1fKoBOHZMG2Js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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