SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '104bebf0c6daf67f40014a60aa42274da008af1fc7dc75f137784cf8cac417e2' 
  AND token = 'BOT9EENN8Ad1nUGUlCvVIXcKlGtXFqJG0Xp4vChb2ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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