SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a4a3f491cb1c3300bfe5a89de373f905f5d863a16559dc25ec127edb38ddc81' 
  AND token = 'Dr7MX9ruh+RegNJuVvTTPBAwzhU7sqgzhv5WyOyxRtE=' 
  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"
    }
  }
}