SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6230820d0ca5cd1aeddafe007db133c56d7a60af41e5bc9931be3050db6d701d' 
  AND token = 'VekAER3DCgKvHu3suwxNuoBIjYw64ETonC3mBCHIdjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}