SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae162d51212a8a8d295b966d09cc7928df887213de72190423c348537bef5e11' 
  AND token = 'RGiqtpcLxwW/pf/hB/TJNp49WMezN2sgPUoInvfo5ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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