SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd00339096e082485941ee0e9cb6eb79dc0122c9b25a38d7ce773b4162ce556' 
  AND token = 'zp8z9iLnnMAMl9HoVIzeNxjKW1LhLuyQN8TuscE2MUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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