SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479d5b33ddaefc4bc4307b24e01c645c9f1c70297539f8ed2d321d54fe595e8a' 
  AND token = 'BHuysBhk2zZR46XGGmf9f4WLaK+/VXfo5Rn+8J3+yqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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