SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5816b2f948eedd0cfd52f6cc91e8d9c44750b4188012aeb2b3acb7a32f32d2c6' 
  AND token = '/HoTsJHByE9FenahoJiTuLPGTfLiX1IYDSdSvQfgz8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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