SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1b1628e61ee2fc684517503c90fb51e27d273fcf56f9c75f2cfedc2c9dc0b1be' 
  AND token = 'ul2kfIpyxhZshk1ZoU5uHZLRKDDwHkvQ+txYnAFcrlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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