SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a384a4214d7ea6c139c2bed6d67e7a3b436bedd859e373d7e1062945616ace1e' 
  AND token = 'g3dQnHtpJG3g5HfLUtWJftiEwXJCJ7d66CZ9FT33WtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}