SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17ef3c71fb97d829398ff44c3df362bc29b07c2477d41c7615a9a743add640b8' 
  AND token = 'pk9MsSd2TUpEvWJzmFB9SCJqj8G8O6zXsgjoVlvozbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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