SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4afd0da9a40395c174510c503d70c91e04215ec63a23ca91413cac326e23beb7' 
  AND token = '7yaJxQs401cDBlza0wYV+8XkGdwFA8WPRj4w/QUaacI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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