SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad958c9b924ff136b3c95c832fdb7fbc2bc9661a067603fc660274e001005446' 
  AND token = 'sTQR4X8DhlBNtmqJYuA5jPnBoN2tv7haf6DvBnvuWIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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