SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53582426609fe6403f8ccfa3e917065486dd8e89ba904d14cbedc924356b1b11' 
  AND token = 'BnVbAXmJ8wWIGABsJ3WZRxhu88sHdzpLGW62u/uiwyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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