SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f99efd2e2922ffcde2dd07953e49065f261f8642297dd5334007e852688ef1d' 
  AND token = 'yxPh3X/leJlBZgE0Kim85i3d1IIgxCQopp8Z4HUTvCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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