SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f727b30c1a8a306f716ed169968db0ceb2785519cd4e705d6df8cce3e8355cba' 
  AND token = 'v4lqtomVn2HHTzCdLeZYs5sPJo55Q3Hw/B6lILX/QtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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