SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43e2c829d7b8c5e90021ffc80a58fccd838dc82224dbc962fd3633a0c7a4553a' 
  AND token = 'tdJjnCpU7snAyAr4qZup6dHSGWN5b2F9qlqAeXheecM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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