SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e082aefd3f17d0a6cff533444e43da96aa50e091615cb7573ba28d938a399e' 
  AND token = 'vRQluicvvs35xHODsHBy28YFCfCDFtfuKI3/2jnyP7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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