SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3081e8eb64733d72d211c4cfaa4fa985998cdd1945e4bb622a20494b2209ada7' 
  AND token = '1esMc5QFV5oa3Hje4AxN5Fwe75cU+qMrTAdl8acF208=' 
  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"
    }
  }
}