SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99c3acc43a4d788615b7b564e0f4c66eac80cb5d4f80977cfc65e85ed4450f1e' 
  AND token = 'IkjaxErrmAl03tRVHe6GvhjOtI6DBP4TkGu9hhVJRi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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