SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af589398c225652843cae45c201b1c730bca7e279082179789eda056e9abcf54' 
  AND token = 'MVUxec689aPc/I21a2bFsc0I8KdVodEUare7ZeIxG5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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