SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f872470c8f28f3214855d81fa5bf7418046f7388a28cc5e097f4ccf5b52749c' 
  AND token = 'Bu3XlArIJTHlPDWSzLav43MV8qvfKvBOAxplZvSFgY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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