SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96651cab589a0f85de31f995c56b011798837969c2d0f7971ae6bc77a6f0482f' 
  AND token = 'Tz5Ha13MXPVy8If/zokSouMfQHyjVqN8DCyupvMgrIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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