SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49cc0d600f194bcaec8794099ad0663dec570134e98b147cf3a6423493f263a3' 
  AND token = 'bbuN1j5Zf6TxhB/GECw/MpZmmGTGUUs9wAvAB0qPM2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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