SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35b385989a064d7b0d9b288e6ceb60a42b163e89d1ed17f27e2961cf5332b6e6' 
  AND token = 'UZAoIjbpihggvpZhzvVswPb6dTnOdrzMdlxLkhH/YJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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