SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cfedbcac44f8c79c2b3191864e7e38d8fc8735aeaa0403716f5f2512c12d2182' 
  AND token = 'knBz5lJbbA80L+0nkOHm0ZY4udN/gsHxkq38fzFrK80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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