SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cbdba6de5fc517e0fd3f41c7e52acab6c26b7c834b1efaf790cc0ea5dd9951a' 
  AND token = 'mEZ+0bVpnDm5utmwK/zNPhrCBhzGDTw3lUJgKc0YuuE=' 
  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"
    }
  }
}