SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02d27e7920278e182a51c8d8669c2c5b395384723ff6eb9b5f11c8e652da6f4d' 
  AND token = 'vArg9rc5gI5nvnE/Ky3U9hOlldlKgWsB+InaF4Ua310=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}