SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36ec82522da1b0fcab16b7434a325605ed124dd9220795e178823e555daa27db' 
  AND token = 'nlSxc9xNtc9Ivdvudg7DRvWIEU3ecZCCB0LjQ8XWSYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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