SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74fd049c45557ac00bf33dfd50d327ec71fb4cd362a43940821573d01ed48654' 
  AND token = 'XUGENcHQz1SDSCzDdCD41VSSJKzG7uU2of1aPuKurzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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