SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03051c68d0647b46ce9763073145484d6ba329a97e4a48ab51250fe96ba6d75f' 
  AND token = 'GC83y/OKFFjhJbXftV+KuGt+YzdxG92jG7ifgJpsgn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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