SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01f83178be56fa8bf7f6007a3dbc7a4ba44b5a582d1c8bfd33e94183e89cfdd7' 
  AND token = 'DBsZr1z/jAwIowv3yxcBfOJWvqjsynh0M5tlvLvEYa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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