SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66956a310f43c6987af60b8a4aa9a8c861848f08725cdda5c2cb59e33bb6c3f7' 
  AND token = 'zGwDhfXuYxnl1akRXjfHUY3nOYYRZw0L8Pdlhmb/FlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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