SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00450cc1875eaa47e2ff58f63169121f5bb3bf49624dafb382764bb17560fcc8' 
  AND token = 'OWSgGwtRnOnO2ZJk6X1sjjTmBm6NywzljHhIVh++EdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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