SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f220e6ce24aaf0b339de837d344583fc6cf2998624c73a754094fcee69a0c6cb' 
  AND token = 'nmzHcbNVQVg+gkB9UauC/WhRvJZ7A/V3mnKHKORJaxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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