SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78062491515a5418087f511c2eba0cf073e69fab9ee2b4d031d0d20b6028175e' 
  AND token = 'pRxMzvvJxRf5kLvFpWGB0VKEhhhjJIG9bj2rJjFC/bU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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