SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35cc7b89990bdbe73c4a573032f7e6994cf24a6baab68e0981265dbe9597d6ec' 
  AND token = 'Qv48xF4L1ZYAgW6OCAeAJz2wVvCL+P8BLk8Z2O0vySw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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