SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54126a58e4a7ee26cb415a45d13dc043ecea2dab3925191a8f0822277b30a6f8' 
  AND token = 'zi/7WPwwZY0MrdspLKL1KJjhHrwsUiEXD+XV0kk06zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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