SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5c4d781caa7f2014ca64a6a63d07a8f660c91edf631f56577ade2cccc1ad51b' 
  AND token = 'GqeFnmuG/tGQBaKKcrh/xHJ2ycj5IMSJnIEDuZhgLCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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