SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c01bcb76c8a8375a047f77d4b1f452073210514362ec45d2dc99a5b2a1f57b1f' 
  AND token = 'tdlCwmCiFqS+ayvFj/H8d/Q4z+da8m9JsVjs0L8JYdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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