SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44b6ee4fdf6acca33834207d742647ac1d0b41213b53a9e90dc985e87f337694' 
  AND token = 'TSITydaw3oaU4wdSGHhuwnqrxhk82sTG9jbWIgbEmw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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