SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd41e98bd209618d340a9a4f9a19928520d6144cf943b9cc7c7a9622d81c9284d' 
  AND token = 'BEiV4Wz7RYyJf1HZi2hm+6VXra4mpDf48uIJtcZs0uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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