SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe439586f68444580bd98ddcf47499a70eaeda9505e1e78a367d919f2ae3e637' 
  AND token = '5XGfsXTP8R1ql4O3nBSmQ83gXZjn/kDLsw7YFUiLIQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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