SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '752cc95ce94382aa2d8aaed3468d7ecf41f3ca8109ef541070d4b1f21576e035' 
  AND token = 'qxQsAlC0f95f7mXXtsuirVEb7sCzUEMmABHhtJ4qQaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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