SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5db55e65f6f58dd02f2aa7fe18c277fb0570b8285fb150f1e907cfc9cd43756' 
  AND token = 'GD2NpHpHqjaODBuyTB+jtpHg+YhKSyycUKxmlmo9bZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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