SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '161b4da2acf43fdeba392bc44d762a262b8bb22e34449ff7cfa95827c3aed26b' 
  AND token = '31VN4rpiN0isCSND5jUdEizldE25IYmfgq72emrvDaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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