SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f2f91e8863e3290a6916e98bf7470e972c955ab14d12b34dd266eba89583f6b3' 
  AND token = 'QsVfe5Q7XLjNh+qCZOimUB2xbcPta2MchxNbNXkn1Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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