SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1034bfd36576e2f25ba68f79925977d4534d72c2e8141a51b80137cd925cc675' 
  AND token = 'UnB4kMyuombOU8KGyP39mqrB8AjbXvs0jYh/3qIs6m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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