SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79b359a7a5e9b73afa90334a57c04228f0879f9f0c203fec36dd4a88ad52560d' 
  AND token = 'qGXXSMqXdYZW+68bODQxahWbkeY667he5eZW76NVMpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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