SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '406e1ce0af363fa10f394f913b3622a1af47bc45dcb74e16b5d55132bc6dedd8' 
  AND token = 'AQFbYv8RwzLzJTa2lFe3ip73TBpX+p/rZxaQACChgw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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