SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2b038e4822baa2c5f72796b9e2451c630332879151d9e8e33f575b49dcaa787' 
  AND token = 'YvhzPx3cSl7KkspKvWHQXXI6a7efrYcwNNfL2Kw/wBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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