SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1a13f5659b2366e0709fbe51ad40f2a1d1a6202978794a2fdf5f3447ce7a461' 
  AND token = 'mCvdX+YUYqMlAi7hjkHMOMmOSc/yHjEkn1NtCc4Ib+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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