SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcbf9f686e08e6a96bc7415127b18f40019f46048bc78cfdc574192005192e51' 
  AND token = 'mBYIAojT5/K0wSsPeY5YAFjCaftDI3xYg3d5kNsI3LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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