SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '624de96dcaefc4223043ee0defa957fcfc25b64ce264d31e231afe8f39f4cf80' 
  AND token = 'IKV88czyiqMEDdm+Z+5gZi0Jxm9WYx7bHHU+lWqieLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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