SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00077989c1b32621b9c527a952cd0fa065331aea7c0bc2016365624da7ff508c' 
  AND token = 'c0YHjsHTOz6kGFkafNipAzMuWywEAllliaqSCsOrJT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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