SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '405d646c603b2ed67124a6d705b304c5dee9b7faf7369f5814e6715058ab662d' 
  AND token = 'JUfqoJfHlHTAsr+ze2QicPFfaifmc6GIh7Q3ese2EVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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