SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4982558479ca4b5f115d57795133b5d325962d871cde03393bde00582d68f33e' 
  AND token = 'muJdkfsfE1F7BlOVDotTk00lPdTJ2RYa29fXsjK6wUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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