SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82a0ed6135a57853a5d2302d86411f3b0403113e3f220969904d8b16096ce6ae' 
  AND token = 'EDEBO+5FR6NaurtC8lF6LraYqLK7mgYIr3iKOxhy55E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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