SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '520c29eb87a003b3f06156de14654bf403a2b8b19bf4dfbf29e2b58f4ee54b01' 
  AND token = 'Bdl/X5+frI9ur80EoWQoCHqsO2jWcTkU1YVfeXKqAIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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