SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '204306f85027e487d8b1a7c1a4781197ec68979689fb5be0bad5bbca518172da' 
  AND token = 'aLjLLilwqTmzJ13B/TImJZr80nGzVogsTV9ZOsiB2ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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