SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b67e1281269d752ebbd091fb1fcd54b390be5c815bb329f75eaa3fb39d9395' 
  AND token = 'TfTJLybRnKeCSI44jEAzmcS/bdOZmpo6r+rlmYbCkwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}