SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c16ce11809e9398ba6ac4035a773d43a8caa4e1b507b40e7f381f4777bca6210' 
  AND token = 'Eianua31fqqbliSWLzLO1gYw3XIxlPmJdNP1dDlDk7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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