SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f378bb7f7f60cf889b12bb035863761f3e670c12faa5a4979da72a8bbf826d5b' 
  AND token = 'cDKAKygDjy/0lg/+ujFYG9XNAFR/wkZ0GX0px+E6l5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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