SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7656cf104757aae5b7efefcb0b34ae198b4505a090808f383005a7b330820df' 
  AND token = 'E9GmmEH+puTtAjzpT5sju3OQ85v+XqYizSZOIqOeBzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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