SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98a1aab52551eee8077cb18ca427780ffd39e2fd050f8df4ec61b91f62664ee4' 
  AND token = 'RlqRoYYXJtDEewvBoCX2iZD/T/KEL/AkZRj5WlEiuBE=' 
  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"
    }
  }
}