SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c5cfe578e0521b43663b45ec472f1f360a35915fdee9ee8b83f48fb018f8d37' 
  AND token = 'SMk3/btRuIHYl1mVEZQfwJ6kmqUIPVZ5oSQz9Y8hRsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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