SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd6afc361374e133c7642cfa6bc9110522a3cf5aa0d0d8572f37d16bf6a97c3' 
  AND token = 'm9VEunrwjJQRVXLhGN59GdO6jYdWn1H+bkxKIrrVlZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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