SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe8c6b9bb24979f65337ac877e20801edfe15ed972b8199b846f424fb3038ee0' 
  AND token = 'y4uXQQ4fho7ycGQfjHXR/QE7vrwERTGHJGx6Y/5I4rE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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