SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3c67de7f8f1017f5c34db89979742ef154231690d23d7b5bb8205741c3b8c7d' 
  AND token = 'IzfZYHAdas7tA7def5DvVpz98nAGHgbxZR0MYxrGw3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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