SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cc0d1b915da99a35620f7a3b9823d35cb73549641c43a43ae98485c27650501' 
  AND token = 'ZVUoPNRUGrHKapaUmUmC0+4ijwxnxckOs4A0qCEOVXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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